000060878 001__ 60878
000060878 005__ 20170330113832.0
000060878 0247_ $$2doi$$a10.1063/1.3103244
000060878 0248_ $$2sideral$$a79801
000060878 037__ $$aART-2009-79801
000060878 041__ $$aeng
000060878 100__ $$aGruen, D.M.
000060878 245__ $$aThermoelectric power factors of nanocarbon ensembles as a function of temperature
000060878 260__ $$c2009
000060878 5060_ $$aAccess copy available to the general public$$fUnrestricted
000060878 5203_ $$aThermoelectric power factors of nanocarbon ensembles have been determined as a function of temperature from 400 to 1200 K. The ensembles, composed of mixtures of nanographite or disperse ultrananocrystalline diamond with B 4 C
B4C
, are formed into mechanically rigid compacts by reaction at 1200 K with methane gas and subsequently annealed in an argon atmosphere at temperatures up to 2500 K. The ensembles were characterized using scanning electron microscopy, Raman, x-ray diffraction, and high resolution transmission electron microscopy techniques and found to undergo profound nanostructural changes as a function of temperature while largely preserving their nanometer sizes. The power factors increase strongly both as a function of annealing temperature and of the temperature at which the measurements are carried out reaching 1 µW/K 2 ¿cm
1 µW/K2¿cm
at 1200 K without showing evidence of a plateau. Density functional “molecular analog” calculations on systems based on stacked graphene sheets show that boron substitutional doping results in a lowering of the Fermi level and the creation of a large number of hole states within thermal energies of the Fermi level [P. C. Redfern, D. M. Greun, and L. A. Curtiss, Chem. Phys. Lett. 471, 264 (2009)]. We propose that enhancement of electronic configurational entropy due to the large number of boron configurations in the graphite lattice contributes to the observed thermoelectric properties of the ensembles.
000060878 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000060878 590__ $$a2.072$$b2009
000060878 591__ $$aPHYSICS, APPLIED$$b24 / 107 = 0.224$$c2009$$dQ1$$eT1
000060878 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000060878 700__ $$aBruno, P.
000060878 700__ $$0(orcid)0000-0002-2071-9093$$aArenal, R.
000060878 700__ $$aRoutbort, J.
000060878 700__ $$aSingh, D.
000060878 700__ $$aMing, X.
000060878 773__ $$g105 (2009), 073710 [10 pp.]$$pJ. appl. physi.$$tJOURNAL OF APPLIED PHYSICS$$x0021-8979
000060878 8564_ $$s1565500$$uhttps://zaguan.unizar.es/record/60878/files/texto_completo.pdf$$yVersión publicada
000060878 8564_ $$s74037$$uhttps://zaguan.unizar.es/record/60878/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000060878 909CO $$ooai:zaguan.unizar.es:60878$$particulos$$pdriver
000060878 951__ $$a2017-03-29-12:05:21
000060878 980__ $$aARTICLE